Human Response to Climate Change during the Umm an‐Nar/Wadi Suq Transition in the United Arab Emirates

Stable oxygen isotope ratios in archaeological human dental enamel represent an under‐utilised tool in the examination of changing climatic patterns in the ancient world. In the Oman Peninsula at the end of the third millennium bc , rapid aridification was accompanied by a breakdown in interregional trade relations; however, the human response to these changes is poorly understood. At the Bronze Age necropolis at Shimal in the United Arab Emirates, dental enamel from individuals interred in both Umm an‐Nar (ca 2700–2000 bc ) and Wadi Suq (ca 2000–1300 bc ) tombs underwent oxygen, strontium and carbon isotope analyses to examine how local inhabitants of southeastern Arabia responded to both environmental and socioeconomic change. While individuals from Shimal exhibit a clear shift in mean δ¹⁸O_c(VPDB) values from the Umm an‐Nar (−3.5 ± 0.6‰, 1σ) to the Wadi Suq (−2.4 ± 0.9‰, 1σ), corresponding ⁸⁷Sr/⁸⁶Sr and δ¹³C_ap signatures display homogeneity indicative of continuity in Bronze Age lifeways. Together, these data highlight the ability of local communities to successfully adapt to their changing environs (in lieu of societal collapse or a shift to a more mobile lifestyle) in an effort to maintain their way of life. Copyright © 2014 John Wiley & Sons, Ltd.     

Stable Isotope Record of Human and Sheep Enamel Carbonate from the Ancient Middle Euphrates Valley (Syria)

Stable isotope analyses of human tooth enamel have allowed us to reconstruct the isotope composition of dietary carbon, changes in the oxygen isotope composition of drinking water and the possible migration of humans in ancient Terqa and Tell Masaikh (SE Syria). δ¹⁸O_carbonate values of human tooth enamel from the interval comprising the Neo‐Assyrian to the modern Islamic periods (from 900 BC to AD 1949) generally mirror the isotope composition of Euphrates water, which is believed to have been a major drinking water source. Lower δ¹⁸O_carbonate values of human Bronze Age apatite are linked to a different hydrologic system that was present in the Middle Euphrates valley at that time (2650–1700 BC). Higher δ¹⁸O_carbonate values of some individuals in the Neo‐Assyrian (900–700 BC) and Islamic periods (AD 600–1200) may indicate human migration from the interior of the Near East. Low δ¹³C_carbonate values (−11.3 to −12.4‰) of human tooth enamel from the interval comprising the Early Bronze to the Islamic periods (from 2650 BC to AD 1200) indicate C₃ plants as a predominant source of dietary carbon. Changes in human dietary customs in SE Syria (with inferred usage of C₄ plants) occurred in the modern Islamic period only (AD 1850–1949). Oxygen and carbon isotope data of sheep enamel show the usage of water bodies characterised by an enhanced evaporation rate during the Neo‐Assyrian time (900–700 BC) and grazing sheep herds on drier areas during the Islamic and the modern Islamic periods (after AD 600). Copyright © 2015 John Wiley & Sons, Ltd.     

Geological constraints on the use of lead isotopes for provenance in archaeometallurgy

The first part of this paper is a brief critical history of the use of Pb isotopes for inferring the geological provenance of archaeological materials, with an emphasis on non-ferrous metals. The second part examines variation in the Pb isotopic ratios of oxide and sulphide ore minerals in selected regions of the world, and relates these to the geological histories of ore formation in each region. This exercise shows that in regions where most ore deposits are of similar geological age—as in the Andes, Europe and the circum-Mediterranean—provenance analysis with Pb isotopes is inherently difficult because geographically distant sources often exhibit similar isotopic ratios. Conversely, regions with many periods of ore formation—such as southern Africa—appear to be very promising regions for future studies of provenance with Pb isotopes. The wider implication of this exploratory survey is that archaeologists should carefully consider the range and clustering of geological Pb isotopic ratios in their regions of interest before investing large sums of money into Pb isotopic analysis of artefacts.     

Neolithic nomadism in south‐east Arabia — strontium and oxygen isotope ratios in human tooth enamel from al‐Buhais 18 and Umm al‐Quwain 2 in the Emirates of Sharjah and Umm al‐Quwain (UAE)

Human skeletal remains from the Neolithic sites BHS18 in the interior of the Sharjah Emirate and the Neolithic shell midden UAQ2 (Umm al‐Quwain) on the coast of the Persian Gulf (United Arab Emirates, UAE) were analysed for their isotope ratios of strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (¹⁸O/¹⁶O). The results are not in agreement with earlier assumptions about a Neolithic nomadism between inland regions and the south‐eastern coast of the Persian Gulf. Existing evidence of nomadic movements of the people from BHS18 most possibly refers to transhumance within the mountains in the hinterland. The strontium isotope measurements on human skeletons from UAQ2 on the contrary indicate uninterrupted residence of this population on the coast. Nevertheless, evidence was found of individual mobility between inland regions and the coast.     

Ancient ‘Black’ Decorative Stones and the Ephesian Origin of Sculptural bigio antico

Isotopic, EPR and petrographic studies aimed at establishing the provenance of sculptural bigio antico are reported, including 18 possible quarry sites and 21 ancient sculptures. The results demonstrate that the Belevi quarry, north‐east of Ephesos, above the more famous white marble quarry, was the major source of this marble. Nineteen artefacts belong to Belevi, whereas the precise origin of the remaining two is unknown, but must probably be found within the same area. The peculiar distribution of δ¹³C values both for Belevi and artefacts was crucial for inferring the correct provenance, subsequently confirmed by additional analytical and petrographic data.     

Monitoring fluid chemistry in iron oxide–copper–gold‐related metasomatic processes,eastern Mt Isa Block,Australia

Most researchers in the Proterozoic eastern Mt Isa Block, NW Queensland, Australia, favour magmatic fluid and salt sources for sodic‐(calcic) alteration and iron oxide–copper–gold mineralization. Here we compare spatial, mineralogic and stable isotope data from regional alteration assemblages with magmatic and magmatic‐hydrothermal interface rocks in order to track chemical and isotopic variations in fluid composition away from inferred fluid sources. Tightly clustered δ¹⁸O values for magnetite, quartz, feldspar and actinolite for igneous‐hosted samples reflect high temperature equilibration in the magmatic‐hydrothermal environment. In contrast, these minerals record predominantly higher δ¹⁸O values in regional alteration and Cu–Au mineralization. This dichotomy reflects partial equilibration with isotopically heavier wallrocks and slightly lower temperatures. Increases in Si concentrations of metasomatic amphiboles relative to igneous amphiboles in part reflect cooling of metasomatic fluids away from igneous rocks. Variations in X_Mg for metasomatic amphiboles indicate local wallrock controls on amphibole chemistry, while variations in X_Cl/X_OH ratios for amphiboles (at constant X_Mg) indicate variable aH₂O/aHCl ratios for metasomatic fluids. Biotite geochemistry also reflects cooling and both increases and decreases in aH₂O/aHCl for fluids away from plutonic rocks. Decreased aH₂O/aHCl ratios for metasomatic fluids reflect in part scavenging of chlorine out of meta‐evaporite sequences, although this process requires already saline fluids. Local increases in aH₂O/aHCl ratios, as well as local decreases in δ¹⁸O values for some minerals (most notably haematite and epithermal‐textured quartz), may indicate ingress of low salinity, low δ¹⁸O fluids of possible meteoric origin late in the hydrothermal history of the region. Taken together, our observations are most consistent with predominantly magmatic sources for metasomatic fluids in the eastern Mt Isa Block, but record chemical and isotopic variations along fluid flow paths that may be important in explaining some of the diversity in alteration and mineralization styles in the district.     

Chemical and isotopic signatures of Na/HCO3/CO2‐rich geofluids,North Portugal

Geochemical and isotopic studies have been undertaken to assess the origin of CO₂‐rich waters issuing in the northern part of Portugal. These solutions are hot (76°C) to cold (17°C) Na–HCO₃ mineral waters. The δ²H and δ¹⁸O signatures of the mineral waters reflect the influence of altitude on meteoric recharge. The lack of an ¹⁸O‐shift indicates there has been no high temperature water–rock interaction at depth, corroborating the results of several chemical geothermometers (reservoir temperature of about 120°C). The low ¹⁴C activity (up to 9.9 pmC) measured in some of the cold CO₂‐rich mineral waters (total dissolved inorganic carbon) is incompatible with the presence of ³H (from 1.7 to 4.1 TU) in those waters, which indicates relatively short subsurface circulation times. The δ¹³C values of CO₂ gas and dissolved inorganic carbon range between ?6‰ and ?1‰ versus Vienna‐Peedee Belemnite, indicating that the total carbon in the recharge waters is being diluted by larger quantities of CO₂ (¹⁴C‐free) introduced from deep‐seated (upper mantle) sources, masking the ¹⁴C‐dating values. The differences in the ⁸⁷Sr/⁸⁶Sr ratios of the studied thermal and mineral waters seem to be caused by water–rock interaction with different granitic rocks. Chlorine isotope signatures (?0.4‰ < δ³⁷Cl < +0.4‰ versus standard mean ocean chloride) indicate that Cl in these waters could be derived from mixing of a small amount of igneous Cl from leaching of granitic rocks.     

Diet and mobility in Middle Archaic Florida: stable isotopic and faunal evidence from the Harris Creek archaeological site (8Vo24), Tick Island

We explore diet and mobility in Middle Archaic Florida using human burials and faunal remains from the Harris Creek archaeological site (8Vo24) on Tick Island. We conducted stable carbon and oxygen isotopic (δ¹³C, δ¹⁸O) analyses of 50 human enamel samples and strontium isotopic (⁸⁷Sr/⁸⁶Sr) analysis of a subset of 10. Most individuals (46/50) subsisted on local freshwater and terrestrial resources, with relatively depleted δ¹³C values (C₃) and δ¹⁸O values matching those of central and north Florida water resources within the St. Johns River valley. Eight of 10 burials have local, within valley ⁸⁷Sr/⁸⁶Sr values. Two human burials yield marine δ¹³C and ⁸⁷Sr/⁸⁶Sr values, which we interpret as evidence for across valley movement from the coast. Another two individuals show depleted δ¹⁸O values, likely obtained from northern rivers. We also identified potential food resources and non-local foods from the Harris Creek faunal assemblage. We found six species with estuarine and marine habitat preferences; two of which, whelk and quahog, indicate that people of Harris Creek traveled to or traded with coastal areas.     

Stable carbon- and nitrogen-isotope ratios and electron spin resonance (ESR) g-values of charred bones: changes with heating and a critical evaluation of the utility of g-values for reconstructing thermal history and original isotope ratios

Changes in the stable carbon and nitrogen isotope ratios of modern bone samples heated to a variety of times and temperatures were used to determine the effect of heating on isotope ratios and the retention of organic matter in charred bones. For organic extracts produced by slow demineralization in weak acid, δ¹³C values were unchanged, while δ¹⁵N values increased by up to 5‰ and were primarily determined by heating temperature. Changes in the electron spin resonance (ESR) g-value of whole bone and organic extracts were also measured. For organic extracts from charred bones, the g-value was well-correlated with δ¹⁵N and temperature, suggesting that g-values could be used to estimate the charring temperature and original δ¹⁵N values of charred bones. Thus, g-values from demineralized extracts could be very useful in forensic investigations where it would important to reconstruct the thermal history of burned bones. Isotope ratios and g-values of demineralized extracts from four prehistoric components at three sites that produced cremated human bone were used to test whether the same approach can be applied to archaeological materials. While carbon isotope ratios of the prehistoric samples were similar to those of uncharred specimens, nitrogen isotope ratios were increased and the g-value corrections for nitrogen isotope ratios were not effective.     

Archaeological excavations at Bosutswe,Botswana: cultural chronology,paleo-ecology and economy

Excavations at the site of Bosutswe on the eastern edge of the Kalahari Desert in Botswana have uncovered over 4 m of deposit ranging in age from CE 700 to 1700. Our research has produced quantitative and qualitative measures of the material and ecological dimensions that structured the everyday actions and behaviors through which social identities were constituted, maintained, and transformed during the period when the polities of Toutswe, Mapungubwe, Great Zimbabwe and Khami rose to power. By examining the material dimensions that underlay shifting relations of production, exchange, and social stratification we are able to contextualize the social judgments that ascribed value to material goods and food ways, while specifying the ways these were used to create and naturalize social relationships and power differentials. Stable isotope analyses, combined with evidence of vitrified dung, further enable us to suggest changes in herd management strategies used by the inhabitants of the site to compensate for ecological changes brought about by long-term occupation, while at the same time enabling them to economically tie subordinates to them as social divisions became more rigidly defined after CE 1300. The cultural and economic changes that took place at Bosutswe thus directly impact our understanding of the social transformations that immediately preceded contemporary configurations of ethnicity in Botswana.